1. Technical Field
The present disclosure relates to an electrolytic capacitor, and more particularly to an electrolytic capacitor having excellent withstand voltage characteristics.
2. Description of Related Art
With digitalization of electronic devices, capacitors used therefor have been also required to have a small size, large capacity, and low equivalent series resistance (ESR) in a high-frequency region.
As capacitors having a small size, large capacity, and low ESR, electrolytic capacitors using a conductive polymer, such as polypyrrole, polythiophene, polyfuran, and polyaniline, as cathode material are promising. For example, there has been proposed a capacitor element including an anode foil having a dielectric layer and a solid electrolyte layer which includes a conductive polymer as cathode material and is provided on the anode foil.
Above all, it is known that significantly low ESR of a solid electrolytic capacitor can be achieved by providing a solid electrolyte layer using poly(3,4-ethylenedioxythiophene) (hereinafter, referred to as “PEDOT”) having extremely high electric conductivity as compared with an electrolyte solution. Furthermore, in the field of a solid electrolytic capacitor using PEDOT or derivatives thereof, many proposals for suppressing leakage current and improving withstand voltage characteristics have been made.